Unknown Kernel (CentOS 2.6.32-754.el6.x86_64)

morrow95

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Oct 8, 2006
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Did a yum update through WHM with a graceful reboot after. The kernel was updated. Since the update I am getting the following email every 4 hours :

subject : Cron <[email protected]> /usr/bin/kcarectl --auto-update --gradual-rollout=auto
body : Unknown Kernel (CentOS 2.6.32-754.el6.x86_64)
 

dalem

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Oct 24, 2003
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That email indicates that you have installed a kernel that either has no Kernelcare patches applied to it as of yet.

you will receive an email every 4 hours (the default frequency that Kernelcare checks for available kernel patches) until Cloudlinux has issued a patch for that particular kernel, and your system has downloaded it and installed it.
 

morrow95

Well-Known Member
Oct 8, 2006
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That doesn't seem like the correct behavior. I used the update within WHM. I have the kernelcare patch applied. Shouldn't ONLY compatible kernels ever be installed? That makes the most logical sense, especially considering this was done in WHM. I could see if I updated the kernel through cli, but within WHM and with the patch I would expect that only kernels compatible could ever be used to prevent this sort of thing from happening.
 

vacancy

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Sep 20, 2012
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The kernelcare patch is specially configured for each kernel.

A few days after the new kernel is released, a new patch will be released by cloudlinux, and the kernelware board will be installed automatically when the patch is released.

Do not worry.
 
Last edited:

cPanelLauren

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The two processes are different, the kernel update then the subsequent kernel-care patch update. In the event you never want to receive a kernel before the kcare patch for it is available you'd need to disable automatic kernel updates which I wouldn't advise.

Thanks!
 

celiac101

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Dec 19, 2012
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Thank you for replying to the poster's concerns, and now you get to hear mine :)

I think the point here is that I've never received this type of email, EVER, in all the years I've run my server. Now I am getting this to. Obviously there is some error, or I wouldn't get a useless email. I mean really, what exactly does this tell me, and why would I need to be sent an email about this???

Unknown Kernel (CentOS 2.6.32-754.el6.x86_64)
 

cPanelLauren

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Hi @celiac101

As indicated before, the email is from a cron job that is created when the KernelCare patch is added. KernelCare checks the kernel periodically to ensure you're using a version KernelCare supports. You're getting the email because your kernel updated before KernelCare patched the new kernel and because of that the kernel version is unsupported by KernelCare.
 

sparek-3

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I suggest that if you want to be angry with someone, be angry with the Kernelcare team. It can take them up to a week or better to release a Kernelcare patch for a new kernel. Is that reasonable? I don't know. But if you are expecting Kernelcare to protect you the very second that a new kernel is released... you've got lofty expectations.

Either way... this is not a cPanel issue.
 

cPanelLauren

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Hi @Gojko

The only reason I can think of that you'd get this notification is if you're using Kernelcare's free patch set for symlink protection as suggested by @sparek-3 and the command suggested by @vacancy would be useful to determine whether or not that's true.

Thanks!
 

celiac101

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Dec 19, 2012
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I never signed up for Kernal Care, yet I'm still getting this message every 4 hours. Perhaps I am using their free symlink protection...no idea. When will this message stop? Do I really have to wait until there is a new kernel update?
 

vacancy

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Sep 20, 2012
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I gave you a command line to control.

Code:
kcarectl --info
We do not know when the kernel patch will come. If there is no special situation, it is sent within 1 week.

Alternatively you can downgrade the kernel. When you install a kernel with patches, the system will activate the kernelcare patch.
 
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cPanelLauren

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This indicates you do indeed have the KernelCare (more than likely the free symlink protection patch) installed but you're using a kernel version that is not currently supported. Once they update to the new kernel you'll stop receiving notifications.

On a server without any kernelcare installed you'll see:

Code:
[[email protected] ~]# kcarectl --info
-bash: kcarectl: command not found